The objective of the whole project is to understand the mechanism of transmitter release from nerve terminals and the life cycle of synaptic vesicles of the central nervous system. The specific aims for the current year include: (a) To characterize coated vesicles that are isolated from bovine cerebral cortex. Especially to elucidate the nature of coat material in comparison with contractile proteins that are associated with a variety of tissues including the brain. (b) To characterize ATPases of subsynaptosomal organelles which may well function using energy released upon the splitting of terminal phosphate from ATP. (c) To isolate and characterize actomyosin-like protein from synaptic constituents which may be involved in transmitter release, and to investigate the distribution pattern of the protein among subsynaptosomal fractions using immuno-chemical techniques. (d) To elucidate the nature of calcium binding of plain synaptic vesicles by sensitive fluorescence technique using Tb3 ion. BIBLIOGRAPHIC REFERENCES: Tanaka, R., and Okumura, K. (1977) Release of neurotransmitters by calcium ionophores, Transactions Amer. Soc. Neurochem., 8, 160. Tsudzuki, T., and Tanaka, R. (1976) On ATPase activity of a fraction of brain synaptic vesicles, J. Jap. Biochem. Soc., 48, 506.